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VulnerabilityPublished Updated

CVE-2026-53090: Linux kernel · bpf: Fix ld_{abs,ind} failure path analysis in subprogs

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in ee861486e377edc55361c08dcbceab3f6b6577bd : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in ee861486e377edc55361c08dcbceab3f6b6577bd, de1055e7f9e67af32b1f3376066272b04e5223c0, d846d83bdacbd8f14fc45c63b8c1d22608452e1c +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 24 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 09b28d76eac48e922dc293da1aa2b2b85c32aeee, < ee861486e377edc55361c08dcbceab3f6b6577bd
Fixed in
  • ee861486e377edc55361c08dcbceab3f6b6577bd
LinuxLinuxAffected
  • ≥ 09b28d76eac48e922dc293da1aa2b2b85c32aeee, < de1055e7f9e67af32b1f3376066272b04e5223c0
Fixed in
  • de1055e7f9e67af32b1f3376066272b04e5223c0
LinuxLinuxAffected
  • ≥ 09b28d76eac48e922dc293da1aa2b2b85c32aeee, < d846d83bdacbd8f14fc45c63b8c1d22608452e1c
Fixed in
  • d846d83bdacbd8f14fc45c63b8c1d22608452e1c
LinuxLinuxAffected
  • ≥ 09b28d76eac48e922dc293da1aa2b2b85c32aeee, < ce01a4e5cfac7adbe0be565f90cd32ecbb2f8337
Fixed in
  • ce01a4e5cfac7adbe0be565f90cd32ecbb2f8337
LinuxLinuxAffected
  • ≥ 09b28d76eac48e922dc293da1aa2b2b85c32aeee, < 8674e2db06cff6b50f2216eed9a761d15425bb34
Fixed in
  • 8674e2db06cff6b50f2216eed9a761d15425bb34
LinuxLinuxAffected
  • ≥ 09b28d76eac48e922dc293da1aa2b2b85c32aeee, < 928d354ae3557e8f755a227e67be88034eb3cd7f
Fixed in
  • 928d354ae3557e8f755a227e67be88034eb3cd7f

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix ld_{abs,ind} failure path analysis in subprogs Usage of ld_{abs,ind} instructions got extended into subprogs some time ago via commit 09b28d76eac4 ("bpf: Add abnormal return checks."). These are only allowed in subprograms when the latter are BTF annotated and have scalar return types. The code generator in bpf_gen_ld_abs() has an abnormal exit path (r0=0 + exit) from legacy cBPF times. While the enforcement is on scalar return types, the verifier must also simulate the path of abnormal exit if the packet data load via ld_{abs,ind} failed. This is currently not the case. Fix it by having the verifier simulate both success and failure paths, and extend it in similar ways as we do for tail calls. The success path (r0=unknown, continue to next insn) is pushed onto stack for later validation and the r0=0 and return to the caller is done on the fall-through side.

References

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